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PRECIOUS STONES.
By George F. Kunz.
Gem mining.—During
1887 no work was done either at Mount Mica, Paris, Maine, or at Stony
Point, North Carolina, which are the two most noted localities where
gems are sought for systematically. At Mount Apatite, Auburn, Maine,
some work was carried on during the fall of 1887; $200 worth of
tourmalines and $400 worth of other minerals were found.
Several
localities in North and South Carolina and Kentucky have been opened
and ordinary mining operations carried on for the purpose of producing
zircon, and several other comparatively rare minerals which have been
only looked upon as gems heretofore, but are now used for making the
oxides of zirconium, lanthanum, cerium, etc. These oxides are needed
for manufacturing purposes.
The
following table gives an approximation of the value of the gems
produced in the United States during the past five years. It does not
include about 20 tons of zircon and quite large -quantities of
allanite, monazite, and samarskite which were mined for use in
manufactures as stated above.
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555
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